Circuit arrangement for current limiting and electrical system

A circuit arrangement (5) for current limiting, the circuit comprising:

• an inductor (L),
• a limiting resistor (RB),
• a gate resistor (RG),
• a current limiting control circuit (10),
• a semiconductor switch (20), and
• a gate driver (25),
• wherein
• an output terminal (12) of the current limiting control circuit (10) is connected to a control input (22) of the semiconductor switch (20) via the limiting resistor (RB), wherein the output terminal (12) is connected between the control input (22) of the semiconductor switch (20) and the gate resistor (RG),
• the gate driver (25) is connected via the gate resistor (RG) to the control input (22) of the semiconductor switch (20) and to the limiting resistor (RB) and is configured to control the semiconductor switch (20) to open and close,
• the current limiting control circuit (10) is configured to change an output impedance of the current limiting control circuit (10) at the output terminal (12) in order to control the semiconductor switch (20),
• the semiconductor switch (20) is configured to set a current (I) in a circuit between an electrical power source (30) and a load (40) as a function of a control by the current limiting control circuit (10),
• the inductor (L) is configured to be directly or indirectly connected to a terminal (32) of the electrical power source (30) via a first terminal (L1) and directly or indirectly connected to a terminal (42) of the load (40) via a second terminal (L2),
• a first input terminal (14) of the current limiting control circuit (10) is electrically connected to the first terminal (L1) of the inductor (L) and a second input terminal (16) of the current limiting control circuit (10) is electrically connected to the second terminal (L2) of the inductor (L), and
• the current limiting control circuit (10) is configured to detect an overcurrent-related voltage drop (VL) of the inductor (L) and in response reduce its output impedance in order to thus increase an output impedance of the semiconductor switch (20) on the basis of a voltage drop across the limiting resistor (RB), so that the increased output impedance in the semiconductor switch (20) counteracts the overcurrent;
• and
• wherein the circuit arrangement (5) is configured to subject, prior to processing by the current limiting control circuit (10), a signal representing the voltage drop (VL) across the inductor (L) to low-pass filtering by means of a low-pass filter (50), which is designed to smooth interference signals acting on the circuit.

A circuit arrangement (5) for current limiting, the circuit comprising:

• an inductor (L),
• a limiting resistor (RB),
• a gate resistor (RG),
• a current limiting control circuit (10),
• a discharge resistor (RD),
• a low pass filter (50),
• a semiconductor switch (20), and
• a gate driver (25),
• wherein
• an output terminal (12) of the current limiting control circuit (10) is connected to a control input (22) of the semiconductor switch (20) via the limiting resistor (RB), wherein the output terminal (12) is connected between the control input (22) of the semiconductor switch (20) and the gate resistor (RG),
• the gate driver (25) is connected via the gate resistor (RG) to the control input (22) of the semiconductor switch (20) and to the limiting resistor (RB) and is configured to control the semiconductor switch (20) to open and close,
• the current limiting control circuit (10) is configured to change an output impedance of the current limiting control circuit (10) at the output terminal (12) in order to control the semiconductor switch (20),
• the semiconductor switch (20) is configured to set a current (I) in a circuit between an electrical power source (30) and a load (40) as a function of a control by the current limiting control circuit (10),
• the inductor (L) is configured to be directly or indirectly connected to a terminal (32) of the electrical power source (30) via a first terminal (L1) and directly or indirectly connected to a terminal (42) of the load (40) via a second terminal (L2),
• a first input terminal (14) of the current limiting control circuit (10) is electrically connected to the first terminal (L1) of the inductor (L) and a second input terminal (16) of the current limiting control circuit (10) is electrically connected to the second terminal (L2) of the inductor (L),
• the current limiting control circuit (10) is configured to detect an overcurrent-related voltage drop (VL) of the inductor (L) and in response reduce its output impedance in order to thus increase an output impedance of the semiconductor switch (20) on the basis of a voltage drop across the limiting resistor (RB), so that the increased output impedance in the semiconductor switch (20) counteracts the overcurrent, and
• the discharge resistor (RD) is connected in parallel with a capacitor (C) of the RC low-pass filter and is defined as a function of a desired duration of the current limiting between the power source (30) and the load (40).